Greases and lubrication

Between 30 and 40 percent of bearing failures are lubrication-related: wrong grease, too much grease, too little grease or expired grease. It is the most frequent cause and the cheapest to correct.

Grease is oil held in a soap. The soap defines how it behaves with temperature and water; the base oil defines what speed and load it is suitable for. That's why two greases of the same color can be incompatible with each other, and mixing them is worse than not greasing.

Lithium greases are general-purpose: they cover most industrial applications at normal temperature. Extreme pressure (EP) greases contain additives for high load and shock, which is what a mill, a crusher or a heavily loaded spherical roller bearing demands. High temperature greases last where a lithium grease dries out and leaves the bearing without support. And food grade greases are mandatory where there is incidental contact with product.

The second is how much and how often. An overfilled bearing heats up from churning its own grease and fails just like a dry one. The amount depends on the size and the revolutions per minute, and the interval shortens with temperature: for every ten degrees more, the interval is cut in half.

If you tell us what machine it is, what temperature it operates at and whether it is washed with water, we'll tell you which grease to use. It's a two-minute question that avoids a plant shutdown.